1. Field of the Invention
The present invention relates to a positional information providing system, a navigation system, and a terminal device.
2. Description of the Related Art
For background technologies of the technical field, there is Japanese Patent Application Laid-Open Publication No. 2005-070115. The following is described in the publication. When a user manipulates a cellular telephone 3, the cellular telephone 3 detects latitude, longitude, and height at a present position, and sends latitude and longitude to a geographic information service server. When the geographic information service server receives the latitude and the longitude from the cellular telephone 3, the geographic information service server searches a sea level database for sea level data corresponding to the latitude and the longitude, and generates a map image including the latitude and the longitude on the center. The geographic information service server sends the sea level data and the map image to the cellular telephone 3. The cellular telephone 3 calculates a story number of a building from the detected height, the height of the story, and the sea level data, and displays the story number together with the map image.